B-17 crashes due to confusing controls - any info?

[technique72]

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

 

[N4521U]

Modern planes use that configuration!

 

[technique72]

Modern planes use that configuration!

Thanks. Yes, I have since found this out.

Would like to see photographs of this layout, as all images I find have full view of the cockpit not detailed shots.

 

[N4521U]

This is true.
(Misinformation deleted)

 

[swampyankee]

One of the WW2 inventions that save numerous lives was the checklist. After a mission lasting 10 or more hours, a significant portion of which involved being shot at, pilots and copilots were doubtless deeply in the world of fatigue, which is the sort of condition in which humans make mistakes. The pilot-copilot hierarchy and military chain of command could also have been a source of this sort of problem: the copilot would be unlikely to tell the pilot that he's just confused the landing gear and flap control. It took into the 1980s or so for the cockpit hierarchy to be transformed from a superior-inferior relationship to a collaborative and cooperative one.

 

[N4521U]

Go here in this forum.
B-17 Manuals
See post #31
Open the Pilots Manual.
Password for this manual is"ez"
See the diagram top of page 53, legend is below for switches controlling Flaps and Landing Gear.
Cheers, Bill

 

[technique72]

This is true.
However close look to left of throttle quadrant looks like Throttle Lock,
At very front Under the throttle levers to the right looks the propeller control lock.

My observation anyway.

Hi N4521U

Do you mean on the front here?

 

[technique72]

One of the WW2 inventions that save numerous lives was the checklist. After a mission lasting 10 or more hours, a significant portion of which involved being shot at, pilots and copilots were doubtless deeply in the world of fatigue, which is the sort of condition in which humans make mistakes. The pilot-copilot hierarchy and military chain of command could also have been a source of this sort of problem: the copilot would be unlikely to tell the pilot that he's just confused the landing gear and flap control. It took into the 1980s or so for the cockpit hierarchy to be transformed from a superior-inferior relationship to a collaborative and cooperative one.

That's an interesting observation. Thanks

 

[N4521U]

Hi N4521U

Do you mean on the front here?

Abandon what I wrote, see my last post it's the straight skinny.

 

[technique72]

Abandon what I wrote, see my last post it's the straight skinny.

Thank you! This is great.

So on page 17, it shows that the landing gear and flap switch are beside each other. Hard to see because of quality.

 

[YGBSM]

One of the WW2 inventions that save numerous lives was the checklist. After a mission lasting 10 or more hours, a significant portion of which involved being shot at, pilots and copilots were doubtless deeply in the world of fatigue, which is the sort of condition in which humans make mistakes. The pilot-copilot hierarchy and military chain of command could also have been a source of this sort of problem: the copilot would be unlikely to tell the pilot that he's just confused the landing gear and flap control. It took into the 1980s or so for the cockpit hierarchy to be transformed from a superior-inferior relationship to a collaborative and cooperative one.

This. So much this.

Source: historicwings.com


An excerpt from The Checklist Manifesto by Atul Gawande:

On October 30, 1935, at Wright Air Field in Dayton, Ohio, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build the military's next-generation long-range bomber. It wasn't supposed to be much of a competition. In early evaluations, the Boeing Corporation's gleaming aluminum-alloy Model 299 had trounced the designs of Martin and Douglas. Boeing's plane could carry five times as many bombs as the army had requested; it could fly faster than previous bombers and almost twice as far. A Seattle newspaperman who had glimpsed the plane on a test flight over his city called it the "flying fortress," and the name stuck. The flight "competition," according to the military historian Phillip Meilinger, was regarded as a mere formality. The army planned to order at least sixty-five of the aircraft.

A small crowd of army brass and manufacturing executives watched as the Model 299 test plane taxied onto the runway. It was sleek and impressive, with a 103-foot wingspan and four engines jutting out from the wings, rather than the usual two. The plane roared down the tarmac, lifted off smoothly, and climbed sharply to three hundred feet. Then it stalled, turned on one wing, and crashed in a fiery explosion. Two of the five crew members died, including the pilot, Major Ployer P. Hill.

An investigation revealed that nothing mechanical had gone wrong. The crash had been due to "pilot error," the report said. Substantially more complex than previous aircraft, the new plane required the pilot to attend to the four engines, each with its own oil-fuel mix, the retractable landing gear, the wing flaps, electric trim tabs that needed adjustment to maintain stability at different airspeeds, and constant-speed propellers whose pitch had to be regulated with hydraulic controls, among other features. While doing all this, Hill had forgotten to release a new locking mechanism on the elevator and rudder controls. The Boeing model was deemed, as a newspaper put it, "too much airplane for one man to fly." The army air corps declared Douglas's smaller design the winner. Boeing nearly went bankrupt.

Still, the army purchased a few aircraft from Boeing as test planes, and some insiders remained convinced that the aircraft was flyable. So a group of test pilots got together and considered what to do.

What they decided not to do was almost as interesting as what they actually did. They did not require Model 299 pilots to undergo longer training. It was hard to imagine having more experience and expertise than Major Hill, who had been the air corps' chief of flight testing. Instead, they came up with an ingeniously simple approach: they created a pilot's checklist. Its mere existence indicated how far aeronautics had advanced. In the early years of flight, getting an aircraft into the air might have been nerve-racking but it was hardly complex. Using a checklist for takeoff would no more have occurred to a pilot than to a driver backing a car out of the garage. But flying this new plane was too complicated to be left to the memory of any one person, however expert.

The test pilots made their list simple, brief, and to the point—short enough to fit on an index card, with step-by-step checks for takeoff, flight, landing, and taxiing. It had the kind of stuff that all pilots know to do. They check that the brakes are released, that the instruments are set, that the door and windows are closed, that the elevator controls are unlocked—dumb stuff. You wouldn't think it would make that much difference. But with the checklist in hand, the pilots went on to fly the Model 299 a total of 1.8 million miles without one accident. The army ultimately ordered almost thirteen thousand of the aircraft, which it dubbed the B-17. And, because flying the behemoth was now possible, the army gained a decisive air advantage in the Second World War, enabling its devastating bombing campaign across Nazi Germany.

 

[MIflyer]

In order to help train thousands of pilots quickly to fly complex airplanes in WWII one of the innovations was the checklist. But this went far beyond the type of thing we use during start-up. Pilots were told Do Item 1 1, Do Item 2, etc. not just on start-up but through the whole flight. Eventually they would become experienced enough to be able to not have to rely on the checklist approach or when to deviate from it.

A former RAF pilot who flew Wellingtons and Dakotas in WWII told me of an incident he observed. I questioned if the crew doing a walk around on something like a multi-engined bomber was worthwhile, given that a ground crew had been working on the airplane for some hours before and were far more qualified to spot problems. He replied, "No", a walk around was valuable. He once saw a Wellington crew climb in their bomber and try to take off. The cover was still over the pitot tube and as they went down the runway the pilot, following the checklist mentality, sat and waited for the proper airspeed to show up on the ASI; it never did. The Wellington stayed on the runway, ran off the end, and wrecked, with a number of fatalities.

Another friend told me of an incident that had happened to him. A man of vast piloting experience, retired from the USAAF/USAF/ANG, he had the job of giving periodic check rides at a US Army base. A senior officer resented having to take the check ride and told him, "Look, if I see YOU deviating from the checklist, I'll be the one writing YOU up!" So they cranked up taxied out in a Grumman OV-1, following the checklist exactly. They got to the run up area, set the parking brake per the checklist, did the run-up, checked the instruments, and, all being satisfactory, went to the next item, "Call tower and receive take-off clearance" and when they got the Okay from the tower, advanced the throttles to taxi into position and take off.

The airplane did not move and the reason became obvious at once. The checklist did not say, "Release the parking brake." They stared at each other. Who was going to get written up?

I have read that at some training bases in WWII (RCAF, I think) students who did not raise the flaps after landing were fined. The flaps could be damaged by blowing gravel and other debris. But today, I have seen instructors yell over the radio at student pilots who raise the flaps on Cessna right after landing, because needless flipping of switches while still on the landing roll can lead to the gear being retracted.

Please, mention the source of your pictures if applicable! (More)

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Forums > World War II - Aviation > Technical > Technical Requests >

 

[technique72]

This. So much this.


View attachment 504143
Source: historicwings.com


An excerpt from The Checklist Manifesto by Atul Gawande:

This is brilliant. Thanks so much.

 

[Eli Josephs]

I haven't read the entire thread, but from what I know of the B-17G, this doesn't seem to have been a problem, or at least it was eliminated as an issue from earlier models. The flap switch has a metal "channel" around it, and the gear switch does not. However, the gear switch has a spring loaded flap, that prevents the gear from being raised unless the flap is also raised. The flaps switch does not have this. Coupled with the bright green light on the instrument panel right in front if the flaps switch, it would be hard to raise the gear and not notice. I'm sure these modifications came from earlier mishaps, and probably eliminated the need for the circle/triangle switch modifications on later models.

The pictures are Solidworks models made from the Boeing microfilm for 43-38083, a B-17G-80-BO. You can see the spring loaded flap to prevent gear from being brought up unintentionally, and the red protector for the flap switch. I think that the two switches between them are for lights of some sort, possibly landing lights.

The switches with the red bar in front of them are fuel cutoff switches. The ones below that are fuel boost pump switches. The last four are for recognition lights, I believe.

I think that the gear safety flap started somewhere in the F models, I'd have to pull up the drawing again to check, that might be wrong. It's also possible that the AAF modified this setup after delivery, but I doubt it.

 

[technique72]

I haven't read the entire thread, but from what I know of the B-17G, this doesn't seem to have been a problem, or at least it was eliminated as an issue from earlier models. The flap switch has a metal "channel" around it, and the gear switch does not. However, the gear switch has a spring loaded flap, that prevents the gear from being raised unless the flap is also raised. The flaps switch does not have this. Coupled with the bright green light on the instrument panel right in front if the flaps switch, it would be hard to raise the gear and not notice. I'm sure these modifications came from earlier mishaps, and probably eliminated the need for the circle/triangle switch modifications on later models.

The pictures are Solidworks models made from the Boeing microfilm for 43-38083, a B-17G-80-BO. You can see the spring loaded flap to prevent gear from being brought up unintentionally, and the red protector for the flap switch. I think that the two switches between them are for lights of some sort, possibly landing lights.

The switches with the red bar in front of them are fuel cutoff switches. The ones below that are fuel boost pump switches. The last four are for recognition lights, I believe.

I think that the gear safety flap started somewhere in the F models, I'd have to pull up the drawing again to check, that might be wrong. It's also possible that the AAF modified this setup after delivery, but I doubt it.

View attachment 505022 View attachment 505023View attachment 505024

Cheers, Eli. Those images are great and the improvements make sense. This model seems to be from 1943? So did earlier models have these improvements?

Which makes me wonder about the veracity of the Alphonse Chapanis story.

This is from New York Times
Chapanis discovered that the accidents were the result of poor cockpit design: the bomber's instrument panel had identical side-by-side toggles, one to control the flaps and the other to operate the landing gear. Weary pilots sometimes flipped the wrong toggle during landing, retracting the wheels and causing a crash.

This from Nautil.com
The pilots of certain models of aircraft would safely touch down and then mistakenly retract the landing gears. The massive aircraft would scrape along the ground, exploding into sparks and flames. Chapanis interviewed pilots but also carefully studied the cockpits. He noticed that on B-17s, the two levers that controlled the landing gears and flaps were identical and placed next to each other. Normally a pilot would lower the landing gears and then raise the wing flaps, which act as airbrakes and push the plane down onto the wheels. But in the chaos of wartime, the pilot could easily grab the wrong lever and retract the landing gears when he meant to raise the flaps. Chapanis's solution: attach a small rubber wheel to the landing gear control and a flap-shaped wedge to the flap control. Pilots could immediately feel which lever was the right one, and the problem went away. In this case it was clear that the problem wasn't the pilot, but the design of the technology that surrounded him.

 

[Eli Josephs]

Cheers, Eli. Those images are great and the improvements make sense. This model seems to be from 1943? So did earlier models have these improvements?

Which makes me wonder about the veracity of the Alphonse Chapanis story.

This is from New York Times
Chapanis discovered that the accidents were the result of poor cockpit design: the bomber's instrument panel had identical side-by-side toggles, one to control the flaps and the other to operate the landing gear. Weary pilots sometimes flipped the wrong toggle during landing, retracting the wheels and causing a crash.

This from Nautil.com
The pilots of certain models of aircraft would safely touch down and then mistakenly retract the landing gears. The massive aircraft would scrape along the ground, exploding into sparks and flames. Chapanis interviewed pilots but also carefully studied the cockpits. He noticed that on B-17s, the two levers that controlled the landing gears and flaps were identical and placed next to each other. Normally a pilot would lower the landing gears and then raise the wing flaps, which act as airbrakes and push the plane down onto the wheels. But in the chaos of wartime, the pilot could easily grab the wrong lever and retract the landing gears when he meant to raise the flaps. Chapanis's solution: attach a small rubber wheel to the landing gear control and a flap-shaped wedge to the flap control. Pilots could immediately feel which lever was the right one, and the problem went away. In this case it was clear that the problem wasn't the pilot, but the design of the technology that surrounded him.

Here's what was used when:

All B-17 airplanes 43-37874 and on used the pictured assembly for the central control panel.

All B-17 airplanes from 41-24340 to 43-37874 also used the same assembly, with minor changes, such as nutplates and nuts changing type.

Now, looking at just the Guard Assy. Landing Gear Switch (that's the official name of the spring loaded flap), it was used on all airplanes 41-2393 and on. That means it was used on all B-17E, all B-17F, and all B-17G. In fact, the drawing sheet is also used for the XB-29, and the B-29. You'll also notice that in the margins are drawing numbers for the YB-17, the XB-15, the 299, the B-17D, the B-17B, and the B-17C. I'm not sure why these are in the margins, but my guess is that those drawings reference this one, possibly in retrospect but I can't be sure. Those drawings aren't in the microfilm. You'll notice B-17G isn't shown on the drawing, but that's because nearing the end of development, sub-drawings were no longer always updated with the master, to save time by not doing non-essential work, as I understand it.

What this all means, is that the B-17E all the way through the G had the gear safety guard new from the factory, and it's likely that all earlier models were upgraded to include it as well if they were ever brought in.

 

[gumbyk]

I
I have read that at some training bases in WWII (RCAF, I think) students who did not raise the flaps after landing were fined. The flaps could be damaged by blowing gravel and other debris. But today, I have seen instructors yell over the radio at student pilots who raise the flaps on Cessna right after landing, because needless flipping of switches while still on the landing roll can lead to the gear being retracted.

The procedures that the school I work with are to taxi clear, stop and then retract flaps and carry out after-landing checks. The problem comes when doing touch-and-goes, and you need to retract the flaps for take-off. We've had a twin retract the gear when they went for the flaps, even with the different switch configurations. combination of inexperienced pilot, stressful situation with weather, etc and a number of other contributing factors.

 

[Casca]

Why did the first Boeing B17 test flight crash on takeoff?

Hi - I remember reading something long ago about B17's control issues and was lead to this link -

 

[MiTasol]

Hi everyone

I am new on here.

I am doing some research on the history of the gear and flap controls.

More specifically the incidents of crashes due to pilot confusing the gear and flap controls during landing in B17s.

In 1942, Alphonso Chapanis interviewed pilots who had survived the crashes in these B-17. After weeks of interviews he returned to the cockpit of the plane. He discovered that due to the proximity and similar shape of the landing gear and wing flap levers, a tired pilot thinking he was controlling the wing flaps to control speed, would accidentally retract the plane's wheels on landing, causing obvious catastrophe.

Due to this research, the Air Force attached wheel-shaped knobs to the landing gear control and wedge-shaped knobs to the wing flap controls so they wouldn't get confused.

I am wondering do any of the experts on this forum know any more on this? Does anyone have photographs of these controls before and after modifications were made to them?

Any help would be great. Thanks

Check out the B-17 Pilot Training Manuals on this or other sites for pictures of the controls. I cannot advise where to find photos of early cockpits but others probably will be able to help.

The Brits were a lot slower on the uptake - there was at least on Viscount ended up on its guts because the pilot grabbed the wrong lever, and they were behind his seat to make it worse as he did not even have a visual to help him.

Locked controls is another issue which is why pilots have check lists that require the pilot to ensure he has full and free movement of every control prior to entering the runway. Despite this there are still accidents caused by morons who skip this check

 

[Reegor]

By the way, this story as told by Atul Gawande and many others before him is only partly true. The accident happened as described, in late 1935. It destroyed the only Type 299. The B-17s did not begin flying until 1937. The earliest manual I know of for the B-17 was July 1937.

The first checklist was in 1935, for a Navy aircraft. (At least, this was the first official checklist in a flight manual. Presumably pilots wrote thing on scraps of paper before that, but I have not been able to find any examples.) By 1937, Navy checklists and manuals were more sophisticated than the first B-17 manual. So the Army and B-17s were late to this particular party. It does make for a good story, though.

Another historical footnote: The chief of the Luftwaffe was killed flying his own aircraft in a very similar way: he forgot to release his gust flaps! This was in 1935. I have written all this up for a book I'm working on, and an article "Who Really Invented the Checklist?"

This. So much this.
An excerpt from The Checklist Manifesto by Atul Gawande:

An investigation revealed that nothing mechanical had gone wrong. The crash had been due to "pilot error," the report said. ....While doing all this, Hill had forgotten to release a new locking mechanism on the elevator and rudder controls. The Boeing model was deemed, as a newspaper put it, "too much airplane for one man to fly." The army air corps declared Douglas's smaller design the winner. Boeing nearly went bankrupt.

Still, the army purchased a few aircraft from Boeing as test planes, and some insiders remained convinced that the aircraft was flyable. So a group of test pilots got together and considered what to do.

What they decided not to do was almost as interesting as what they actually did. They did not require Model 299 pilots to undergo longer training. It was hard to imagine having more experience and expertise than Major Hill, who had been the air corps' chief of flight testing. Instead, they came up with an ingeniously simple approach: they created a pilot's checklist. Its mere existence indicated how far aeronautics had advanced. In the early years of flight, getting an aircraft into the air might have been nerve-racking but it was hardly complex. Using a checklist for takeoff would no more have occurred to a pilot than to a driver backing a car out of the garage. But flying this new plane was too complicated to be left to the memory of any one person, however expert.​